Combinatorial Synthesis and Evaluation of 伪-Iminocarboxamide-Nickel(II) Catalysts for the Copolymerization of Ethylene and a Polar Monomer
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- 作者：Shinichiro Fuse ; Hisashi Masui ; Akio Tannna ; Fumihiko Shimizu ; Takashi Takahashi
- 刊名：ACS Combinatorial Science
- 出版年：2012
- 出版时间：January 9, 2012
- 年：2012
- 卷：14
- 期：1
- 页码：17-24
- 全文大小：330K
- 年卷期：v.14,no.1(January 9, 2012)
- ISSN：2156-8944
文摘
Late-transition metal catalysts used for olefin polymerization, the so-called postmetallocenes, which includes 伪-iminocarboxamide-nickel(II) catalysts have attracted a great deal of attention because of many valuable features such as the copolymerization of 伪-olefins with polar monomers. In this paper, the combinatorial synthesis and evaluation of 伪-iminocarboxamide-nickel(II) catalysts are discussed for their roles in the discovery of a highly active catalyst and elucidation of its structure鈥揳ctivity relationship. The combinatorial optimization of each reaction condition was performed, then a combinatorial library of 伪-iminocarboxamides with systematically modified substituents was constructed by amidation of 伪-keto acid chlorides and subsequent imination of 伪-keto carboxamides in parallel fashion. As a result, 87 analytically pure 伪-iminocarboxamide ligands were successfully synthesized. 伪-Iminocarboxamide-nickel(II) catalysts were prepared from the synthesized 伪-iminocarboxamide ligands. The catalysts鈥?activities for polymerization of ethylene and copolymerization of ethylene and 5-norbornen-2-ol were evaluated. Results of the present study revealed 9 novel active catalysts for ethylene polymerization and 7 novel active catalysts for copolymerization of ethylene and 5-norbornen-2-ol. It should be noted that the best catalysts for ethylene polymerization and for copolymerization in the present study showed higher activities compared to the known active catalyst. Polymerization activities of the catalysts varied dramatically according to the combination of substituents on the 伪-iminocarboxamides.